The invention relates to a method for the treatment of fine-grained material in a spouted bed and a corresponding apparatus.
A method and an apparatus are known from DE 103 22 062 A1 for applying liquids into a flow of solid matter in a spouted bed apparatus. These spouted bed apparatuses are characterized, among other things, in that they comprise a rectangular reaction chamber and a fluidizer, consequently arranged in the axial direction of the reaction chamber, in a single or duplicate embodiment. When several reaction chambers are given they are connected to each other via a material overflow. In case of liquids being injected the nozzles required are allocated centrally in the spouted bed apparatus. The fluidizer is embodied in a controllable fashion in order to vary the amount and the flow speed of the processing air. This method and the respective devices are characterized in a linear alignment of the fluidizer.
In such methods and apparatuses it is disadvantageous that there are high requirements with regards to production accuracy of the gas injection device in order to ensure a homogenous flow over the entire length of the apparatus. Furthermore, the longitudinal extension of the apparatus is limited, mandatorily resulting in a deflection of the material flow via the material overflow. Additionally, a large longitudinal geometry of the apparatus results from the longitudinal extension, which leads to the apparatus becoming more expensive.
From DE 31 17 892 A1 a spouted bed apparatus is known for the production of granulates, in which a liquid is inserted into the flow of solid matter in the spouted bed granulator. The spouted bed apparatus exhibits a circular cross-section, with its lower part being embodied conically tapered. A gas channel opens in the central, conical part of the spouted bed granulator, in which a nozzle is arranged for injecting the liquid. A respective gas is fed via said gas channel to maintain the spouted bed. The centrally supplied gas entrains the liquid inserted via the nozzle as well as a portion of the material located in the spouted bed granulator, causing a flow channel to develop in which the material particles are moistened with the liquid. The sprayed material is fed back to the spouted bed via the conical floor so that a circulation of particles develops. When an appropriate granulate size has been reached the particles are removed from the spouted bed granulator.
This type of spouted bed apparatus is disadvantageous in that a homogenous moistening of the material particles with liquid is problematic in such an apparatus and furthermore problems develop in high performance apparatuses with regards to the creation and maintenance of the spouted bed.
The prior art also shows the use of fluidized beds in apparatuses with a circular geometry of the bottom of the spouted bed as well as the entire apparatus for the purpose of dehydration, spray-granulation, agglomeration, or for coating, with the processes being performed either in form of individual charges or in a continuous fashion.